Apple will ship consumer-oriented iMacs and iBooks with higher clock speeds than its flagship Power Mac machines, according to company documents described over at MacOS Rumors.

The plan, according to the documents, goes something like this: Apple will roll-out consumer machines using IBM's PowerPC 750CXe CPU - a G3 class processor - taking iMacs to 733MHz and iBooks to 677MHz. Of course, that leaves current Power Mac G4s running at 500MHz, though this is expected to be beefed up to 600MHz early next year.

But how to make the high-end machines seem superior to the low-end boxes? The G4's 500MHz PowerPC 7400 is roughly as fast as a 600MHz PPC750, but MacOS X's optimisation for the 7400 should give Apple stacks of statistics to show how much faster the G4 is to the iMac.

Of course, once Motorola's 'G4 Plus' CPU ships, possibly sometime during Q2 2001, G4 speeds should rise quickly to 700MHz and beyond, restoring the 'high-end, high clock speed; low-end, low clock speed' ratio, so this is clearly a temporary measure.

As CEO Steve Jobs recently admitted, Apple has got it wrong on the megahertz argument. Like it or not, far too many people view clock speed as the be-all and end-all of computer performance, and on that scale Apple is way behind the Wintel world. Apple's attempt to improve matters with dual-CPU machines clearly haven't helped - to a lot of buyers, the 500MHz G4 looks woefully underpowered compared to, say, a 1.5GHz AMD Athlon.

That's why Apple needs faster G3 class CPUs for the iMac and iBook. The trouble is, its plan to make the G4 appear better seems to rely on benchmarks which, as we've seen, aren't as powerful a sales tool as raw megahertz. And while MacOS X 1.0 will be rather faster than the Public Beta, accelerating applications by speeding up the core APIs they run on, there are going to have to be rather more apps out there than there are now to tempt users over to the new OS, which limits its use as a driver for G4 sales. ®